1. Field of the Invention
The present invention relates to an object, a method, or a manufacturing method. In addition, the present invention relates to a process, a machine, manufacture, or a composition of matter. One embodiment of the present invention relates to a semiconductor device, a light-emitting device, an electronic appliance, a lighting device, a fabrication method thereof, or a driving method thereof. In particular, one embodiment of the present invention relates to a light-emitting device and an electronic appliance that utilize an organic electroluminescence (hereinafter also referred to as EL) phenomenon, and a driving method thereof.
2. Description of the Related Art
Research and development have been extensively conducted on light-emitting elements utilizing organic electroluminescence (EL) (also referred to as organic EL elements). In a basic structure of an organic EL element, a layer containing a light-emitting organic compound (also referred to as an EL layer) is provided between a pair of electrodes. By applying voltage to this element, light emission from the light-emitting organic compound can be obtained.
Since an organic EL element can be formed in a film form, an element with a large area can be easily formed. Thus, organic EL elements also have great potential as planar light sources that can be applied to lighting and the like.
For example, Patent Document 1 discloses a lighting device including an organic EL element.
Cameras are equipped with flashes for taking photographs in dark places. Cameras are required to be small and light enough to be carried easily.